Door mechanism



March 6, 1928. 1,661,719

R. M. EDWARDS ET Ax.

DOOR MECHANISM Filed Aug. 13, 1927 Rog M. Edwards ana' .fa/$1.5 EPoscen.

ATTORNEY Patented Mar. 6, 1928.

UNITED STATES PATENT OFFICE.

ROY M. EDWARDS AND JULIUS P. POSCHEN, OF PITTSBURGH, PENNSYLVANIA.

DOOR MECHANISM.

Application led August 13, 1927. Serial No. 212,622.

Our invention relates to automatic dooroperating mechanism, and it hasparticular relation to such mechanism as applied to an overhead door ofthe type having hinged planels guided, at their ends, in a track which(isposes the door in a horizontal position overhead, when the door isopened.

The principal object of our invention is to provide a thoroughly safeand reliable mechanism which utilizes only a small-size electric motorto operate the same.

A further object of our invention is to provide mechanism whereby areversible single-phase induction motor may safely be utilized.

A still further object of our invention is to provide means whereby themotor may attain a good start before exerting a significant torque onthe door-operating mechanism.

With the foregoing and other objects in view, which will be understoodas the description proceeds, our invention consists in the combinationsand parts described and claimed in the following specification, andillustrated in the accompanying drawing, wherein Fig. 1 is adiagrammatic View of circuits and apparatus embodying an electricalcontrol and driving connections embodying our invention,

Fig. 2 is a side elevational view illustrating the entire assembly,

Fig. 3 is a cross-sectional view on the line III*II of Fig. 2, and

Fig. 4 is a cross-sectional view on the line IV-IV of Fig. 2.

T he overhead door is constructed of a plurality of panels, as indicatedat 5, 6, 7 and 8, which are hinged together, one above another, byoffset hinges, as indicated at 9, 10 and 11. The hinge pintles areextended to support rollers 13 which run in tracks or guides 15extending up along both sides of the door-opening in the front Wall 17of the garage or other building in which the door is installed. The doorguides 15 make a quarter-circle bend 18 near the top of the door andextend back in a substantially horizontal direction overhead, asindicated at 19. One or both of the top and bottom panels 5 and 8 may beprovided with additional guide rollers 21 and 22, respectively, atpoints removed from the hinges 9 and 11.

The door is preferably counterbalanced so that it will remain in anyposition. Any well-known means may be provided to this end, such as achain 24, connected to the lower panel 8-at each side edge of the door,said chain extending up to a fixed pulley 25 at the top of the door,whence it passes horizontally to a spring-supported pulley 26, andforward again to a point of attachment near the head of the door frame Aspring 28 pulls baekwardly on the movable pulley 26 and effects theexact counterbalancing action which is desired.

The door-operating mechanism of our invention relates particularly to anoverhead door of the type just described. One form of embodiment thereofis shown, in the drawing, as comprising a pair of substantiallyhorizontal T-irons 30 slightly spaced from each other to provide arunway for a small trolley or carriage 31 which is movable to the frontand the rear immediately above the overhead position of the door. Thecarriage 31 is connected to the top panel 5 of the door by means of arod or link member 32 which is pivoted at both ends, whereby the doormay be pulled or pushed, to open and close the same.

Movement is imparted to the carriage 31 by means of an endless chain 33which passes over a driving wheel. 34 in the rear and an idler wheel 35at the front. The driving wheel 34 is driven by means of anon-reversible gear mechanism comprising a worm wheel 37 (Fig. l) whichmeshes with a. worm 38 on the shaft 39 of an electric motor 41, which ispreferably a single-phase induction motor having a main primary winding42 and two teaser windings 43 and 44 for starting in either the forwardor the reverse direction.

The motoris controlled by a suitable pushbutton control system, whichmay comprise two doubleole main-circuit relays 46 and 47 for energizingeither the main Winding 42 and the forward teaser winding 43, or themain winding 42 and the reversing teaser winding 44. The main-circuitrelays 46 and 47 are energized by any suitable means, such as twocontrol relays 48 and 49, respectively, which are actuated to closedposition by means of forward and reverse push buttons 51 and 52,respectively. When either of the control relays 48 or 49 is closed, anauxiliary eontactor 53 or 54, as the case may be, completes a holdingk,closed until the olding circuit is broken by a limit switch 55 or 56,respectively, which is actuated by one of two cams 58 or 59 carried by aslowly moving wheel 60 geared to the driving wheel 34. f i

The motor may be stopped at any point by depressing an emergency-stoppush button 61 which open-circuits the holding circuits of the controlrelays 48 and 49. The motor will also be stopped, in case the overheaddoor meets with an obstruction, by means of an overload circuit breaker63 which is adjusted to just barely permit the motor to developsufficient torque to operate the door, thereby limiting the pressurethat can be brought to bear on any obstruction such as an automobile(not shown) in the doorway. breaker 63 also de-ener izes all of therelays, so that the reclosing of the breaker will not cause the motor tore-start until the desired push button 51 or 52 is subsequentlydepressed.

When the motor is dei-energized, 1t 1s immediately brought to rest bymeans of .a spring-pressed brake 65, which is automatically released bymeans of a series solenoid 67 in the motor circuit, when the motor 1sstarted in either direction. The brake not only prevents the motor fromcontinuing to rotate after the door has come into contact with anobstruction, which would increase the crushing force exerted by thedoor. on the obstruction, but it also makes possible the operation ofthe emergency-stop button 61, followed immediately by the reversing pushbutton 52, in case the operator should see an obstruction in the way ofthe descending door. If the brake were not provided,

. with a single-phase induction motor, which is the most practical formof motor, an excited operator, attempting to quickly reverse the motor,might operate the reversing button while the motor is still turning in`the forward direction, in which case, the motor would continue tooperate in the forward direction without reversing. It is no small partof our invention to prevent such an accident by providing an automaticbrake which instantly stops the motor before the reversing button 52can'possibly be depressed after the depression of the stop button 6l.

In operation, the small trolley or carriage 31 rolls smoothly, andwithout binding, along the T-bar runways 30, pushing or pulling the dooralong with it. The carriage and its runway are particularly neeessarywhen the door is in its closed posi# tion, as shown in the drawing, asthen a horizontal backward pull by the chain 33 on the carriage causesthe connecting link 32 to pull obl-iquely upwardly lon the door, therebyraising it and starting its upward circuit to keep the relayl Theopening of the circuit-v movement. If-the carriage were not prolvided,the chain 33 being then connected directly to the top panel of the door,no amount of backward pulling on the chain would raise the door, asthere would be no vertical component to the pulling force on the door.

It is quite desirable, in operation, to provide a yielding drivingconnection, or lostmotion device, between the motor and the door, sothat the motor may make one or more revolutions before encountering muchopposing torque, thereby enormously reducing the starting-torque reuirements. In our present embodiment o the invention, the lost-motionconnection is obtained by means of the slack in the chain 33. It will benoted in Fig. 2, for example, that when the door is closed, the bottomchain is slack, so that when the motor is started kin the reversedirection, to raise the door by pulling back on the carriage 31, theslack in the chain must be taken up before the motor begins to pull hardon the carriage, and

the high-reduction gearing between the mo-4 tor shaft 39 and the drivingwheel 34 makes it necessary for the motor to turn several revolutionsbefore taking up this slack.

It will be noted, further, that the nonreversible gear drive consistingof the worm 38 and worm wheel 37 causes the door to be positively lockedin any position in which the door is stopped.

While we have described our invention in a preferred form of embodiment,we desire it to be understood that such embodiment is illustrative only,and that many changes may be made without departingy from the essentialspirit of our invention. We desire, therefore, that the appended claimsshall be given the broadest construction consistent with their wordingand the prior art.

YVe claim as our invention:

1. The combination' comprising a closure member having hinged panels,guide rollers attached to the ends of the panels, a track for saidvguiderollers, said track having a central curved portion and twosubstantiallyv straight ends corresponding to the open and closedpositions of saidv closure member, respectively, a substantiallystraight runway disposed substantially parallel to but offset vfrom, thestraight end of the track in which said closure member is `in its openposition, a carriage movably mounted on said runway,

and inclined link connecting said carriage to one ofthe KVpanels ofSaidclcsure member, andindependent means for moving said carriagealong'its runway. y i

2. The combination comprising a closure member having hinged panels,guide rollers attached to the' ends of the panels, a track for saidguide rollers, said track having a vcentral `curved portion and twosubstantiallyv straight ends corresponding to the open and closedpositions of said closure member, respectively, a substantially straightrunway disposed substantially parallel to, but offset from, the straightend of the track in which said closure member is in its open position, acarriage movably mounted on said runway, an inclined link connectingsaid carriage to one of the panels of. said closure member, pulleys atthe ends of said runway, an endless exible tension member passing oversaid pulleys and connected to said carriage, and means for driving oneof said pulleys.

3. An overhead door assembly, comprising the combina-tion, with the doorhaving hinged panels, a track for guiding the ends of said panels from-avertical position in which the door is closed to a substantiallyhorizontal overhead position in which the door is open, andcou'nterbalancingl means for approximately counterbalancing the door inany position, of mechanism for opening and closing said door, comprisinga substantially straight runway disposed substantially parallel to, butslightly above, the closed position of the door, a carriage movablymounted on said runway, an inclined linkconnecting said carriage to thetop panel of the door, pulleys at the ends of sa-id runway, an endlessflexible tension member passing over said pulleys and connected to saidcarriage, and means including a non-reversible gear mechanismv fordriving one of said pulleys.

4. An overhead door assembly, comprising the combination, with the doorhaving hinged panels, a track for guiding the ends of said panels from avertical position in which the door is closed to a Substantiallyhorizontal overhead position in which the door is open, andcounterbalancing means for approximately counterbalancing the door inany position, whereby approximately the same force is required to movethe door in either direction at any point in its travel, of mechanismfor opening and closing said door, comprising a substantially straightrunway disposed substantiall parallel to, but slightly above, the closeposition of the door, a carriage movably mounted on said runway, aninclined link connecting said carriage to the top panel of the door,pulleys at the ends of said runway, an endless flexible tension memberpassing over said pulleys and connected to said carriage, a

rime mover for driving one of said pulleys 1n either direction, atthewill of the operator, and automatic means for quickly stopping saidprime mover when the door requires an abnormally large force to move itat any point in its travel.

5, An overhead door assembly, comprising the combination, with the doorhaving hinged panels, a track for guiding the ends of said panels from avertical position in which the door is closed to a substantiallyhorizontal overhead position in which the door is open, of mechanism foropening and closing said door, comprisin a substantially straight runwadisposed su stantially parallel to, but slig tly above, the closedposition of the door, a carriage movably mounted on said runway, aninclined link connecting said carriage to the top panel of the door,pulleys at the ends of sald runway, an endless flexible tension memberpassing over said pulleys and connected to said carriage, a single-phaseinduction motor operatively connected to one of said pulleys, a normallyapplied brake applied to said motor, means responsive to theenergization of'said motor for releasing said brake, and means, underthe control of the operator, for starting, stopping and reversing saidmotor, said brake being operative to stop said motor before saidreversing means can normally be actuated by the operator after theactuation of said stopping means.

6. An overhead door assembly, comprising the combination, with the doorhaving hinged panels, a track for guiding the ends of said panels from avertical position in which the door is closed toA a substantiallyhorizontal overhead position in which the door is open, andcounterbalancing means for approximately counterbalancing the door inany position, of mechanism for opening and closing said door, comprisinga substantially straight runway disposed substantially parallel to, butslightly above, the closed position of the door, a carriage movablymounted on said runway, an inclined link connecting said carriage tothetop panel of the door, a prime mover of relatively high speed, and adriving connection including a lost-motion device for operativelyconnecting said prime mover to said carriage to move the latter ineither direction, said lost-motion device enabling the prime mover toattain a good start before exerting a significant torque on saidcarriage upon starting n either direction.

In testimony whereof, we have hereunto our names this 8th day of August,19 l.

ROY M. EDWARDS. JULIUS P. POSCHEN.

